How brains are built

❶The frontal lobes are involves in memory, spontaneity, initiation, language impulse control, motor functions, as well as sexual and social behavior. By the start of the 19th century, the brain's importance as the organ of perception and higher mental function was beyond doubt.

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Researchers have highlighted the possibility that mirror neurons in human brain are responsible for development of human intelligence and therefore the civilization as we know it. Due to mirror neurons, humans were able to communicate using gestures which evolved into languages. With the rise of languages, humans started to develop and share knowledge which was used for development of the society. In light of the knowledge on human brain available to medical scientists, human brain can be divided into four main parts known as cerebral lobes, which are: The functions of frontal lobe include: Thus, frontal lobe performs all the tasks that contribute towards the intelligence of the individual.

These functions are extremely important as without these functions, an individual may not be able to think and therefore perform any of the day to day tasks. Even today, it's common to find that people think they know more than it's currently possible to know about how and why brains work or go wrong; for example, the causes and cures for various types of mental illness, which may contribute to the social stigma that surrounds these conditions.

Through the late 19th and early 20th centuries, scientists including Pierre Paul Broca, Carl Wernicke, Korbinian Brodmann and Wilder Penfield found credible scientific evidence supporting the subdivision of the brain into discrete areas with different specific functions.

Their work was based on studies of patients with localized lesions of the brain, of the anatomical differences between different parts of the brain and of the effects of stimulating discrete brain regions on bodily actions. Together, scientists such as these laid the foundations of modern neuroscience. As you watch the TEDTalks in Mapping and Manipulating the Brain , notice how the speakers reference some of the same approaches used by Broca, Wernicke, Brodmann and Penfield, and how they apply the concepts of brain regionalization and localization of function.

Bear in mind, however, that although these concepts are useful, they're also controversial -- more on this below. Through his extensive and beautiful studies of the microscopic structure of the brain, he discovered that the neuron is the fundamental unit of the nervous system.

This daunting task would likely be easier if we could follow the process by which the brain is generated, but following brain development is very difficult to do in humans. Thus, we often have to infer how the human brain develops by studying the developing brains of other species, so-called "model organisms" selected for their particular advantages in certain experimental procedures.

Aside from helping us to work out how the adult brain functions, research on brain development is a major area in neuroscience for other reasons as well. For example, many conditions like schizophrenia and autism can be traced back to abnormalities in earlier brain development. The great molecular, structural and functional diversity of brain cells, along with their specializations and precise interactions, are acquired in an organized way through processes that build on differences between the relatively small numbers of cells in the early embryo.

As more and more cells are generated in a growing organism, new cells diversify in specific ways as a result of interactions with pre-existing cells, continually adding to the organism's complexity in a highly regulated manner.

To understand how brains develop we need to know how their cells develop in specific and reproducible ways as a result of their own internal mechanisms interacting with an expanding array of stimuli from outside the cell. Since, as discussed above, regionalization is a prominent organizing feature in mature brains, when and how is it established during brain development?

Some of the most exciting research on brain development in recent years has focused on this question. For neurons to develop regional identities, they must possess or acquire information on where they are located within the brain so that they can take on the appropriate specializations.

How neurons gain positional information has been one of the most prominent themes in developmental neuroscience in the last 50 years or so, as indeed it has in the broader field of developmental biology positional identity is required not only by brain cells.

The model that has dominated current thinking was famously elaborated in the s by Lewis Wolpert in his French flag analogy. Here, a signal produced by a group of organizer cells diffuses from its source through a surrounding field of cells. In so doing, it forms a concentration gradient with more of the signal present in areas closer to the source. Cells respond to the concentration of this signal. In Wolpert's French Flag analogy, they become blue, white or red in reality, they would become cells of different types, not different colors.

Close to the source, cells receive signals above the highest threshold to become blue, or type 1. Beyond this, cells respond to a lower dose to become white, or type 2 while farther still cells do not receive enough of the signal to respond and become red, or type 3. The important point is that cells can work out where they are based on the level of signal they receive and they respond accordingly by developing different attributes.

Beyond Wolpert's basic model, the issue of how brain regionalization develops is an important question and we have relatively few answers. Regional specification is a prerequisite for the development of the connections that must link each region of the brain in a stereotypical and highly precise way but allowing room for plasticity at a fine level. The dorsal vascular wall forms anterior choroid plexus. Its cavity is called diocoel or third ventricle.

On the ventral side hypothalamus forms the floor of the diocoel. It consists of number of scattered masses of the grey matter in the white matter. The pituitary hangs below the hypothalamus by a stalk called infundibulum.

Below pituitary is mammillary body. Two optic nerves cross each other to form optic chiasma in front of the pituitary Fig. Diencephalon regulates manifestations of emotions and recognizes sensations like heat, cold and pain. Hypothalamus contains nerve centres for temperature regulations, hunger, thirst and emotions.

It also produces various neurohormones that control the secretions of anterior pituitary. Hormones of posterior pituitary are produced in hypothalamus and later transported to pituitary. Hypothalamus contains higher centres of autonomic nervous system and controls carbohydrate, fat metabolism, blood pressure and water balance.

The Pineal body or epiphysis is an endocrine gland producing the hormone melatonin which controls pigmentation in certain animals. Recently it has been claimed to function as a Biological clock regulating day and night periodicity. The mid brain connects cerebral hemispheres with cerebellum.

It consists of optic lobes and crura cerebri. There are four, solid optic lobes, which arise from the dorsolateral side of the mid brain. They are collectively called as corpora quadrigemina. In case of frog there are two hollow optic lobes which are together known as corpora bigemina.

The anterior pair of optic lobes are called Superior colliculi and the posterior optic lobes are called Inferior colliculi both are formed of grey matter. The former acts as the centre for visual reflex and the latter acts as centre for auditory reflex. On the ventral side of mid brain in its floor there are two large longitudinal bands of nerve fibres called crura cerebri sing, crus cerebrum which connect the medulla oblongata with the cerebral hemisphere. The cavity of the mid brain is in the form of a narrow canal called iter which connects third ventricle with the fourth ventricle.

The optic lobes are the centres of visual and auditory reflexes. The crura cerebri controls the activities of the eye muscles. Cerebellum is the second largest part of the brain.

Like cerebral hemispheres its upper surface is formed of grey matter and forms cerebellar cortex and the deeper central part is medulla formed of white matter.

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The Human Brain Essay - The human brain is a big, intricate—yet delicate, structure in the human body. It is the key structure in cognitive function. Any damage to the brain does not only “erase” memories but also may “deceive” the brain to erroneously remember a new object as being familiar ().

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The brain forms part of the central nervous system together with the spinal cord. The body's nervous system is the center for communication and decision making. The nervous system is composed of the central and the peripheral nervous system, and the peripheral nervous system is made up of nerves in turn.

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The brain is formed of two types of nervous tissue, Grey matter on the outer side and White matter on the inner side. The former is made of non-medullated nerve cells whereas the latter is formed of medullated nerve cells. The human being is considered to be the ultimate form of life on the. This is not because the human body is strong and agile. Many other. animals posses skills much superior to humans and are able to perform feats. humans can only dream of. The one thing that distinguishes humans from all. of the 3/5(9).

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The Human Brain Essay Words | 5 Pages. The human brain is a big, intricate—yet delicate, structure in the human body. It is the key structure in cognitive function. Any damage to the brain does not only “erase” memories but also may “deceive” the brain to erroneously remember a new object as being familiar (). Human brain is the most complex organ in the human body. Despite centuries of advancements in medical sign, the entire functionality of the human brain remains a mystery for medical experts as new types of neurons and brain functions are discovered every now and then.